3. (18 marks) Let P(x), Q(x), and R(x) be the following predicates: P(z) : x2-7x + 10 = 0 Q(z) : 2,2-2-3=0 R(x):0 (a) Determine the truth or falsity of the following statements, where the universe is all integers. Briefly explain your answers in precise English i, Vz, (P(z) ~ R(z)) ii. Vz, (Q(x) R(x)) iii, 30, (P(z) R(z)) (b) Find the answers to part (a) when the universe consists of all positive integers (c) Find the answers to part (a) when the universe contains only the integers 2 and 5